Coconut crabs, which can grow up to 3 feet, now proven to prey on birds

terrestrial arthropod (and thought to represent the upper size limit for land-dwelling creatures supported by exoskeletons), coconut crabs can grow to more than 3 feet in length. They can climb trees and crack coconuts. Their claws are as strong as a lion’s jaws. They can live for up to 60 years. And now, researchers have evidence that their diet isn’t limited to fruits, nuts, and scavenged carrion: they sometimes engage in predation, as well.

It has long been known that the crabs will feed on meat, when they encounter it; in a 2007 experiment, coconut crabs made short work of a small pig carcass, quickly stripping its flesh and scattering the bones. Persistent rumors suggest that a dead or wounded Amelia Earhart may have suffered a similar fate. Researchers now have direct evidence, though, that coconut crabs will not only consume dead animals they come across, they will sometimes go on the hunt themselves.

[N]ow, finally, we have video evidence that the crabs — thousands strong on one island — can scale trees and hunt full-grown birds in their nests.

[…] After about a month on the island [in the Chagos archipelago], in February of 2016, [Dartmouth biologist Mark Laidre] investigated a giant crab’s underground lair. “Deep inside the crab’s burrow was the carcass of a nearly full-grown red-footed booby,” he wrote. This was Laidre’s first sign that the stories might be true, that giant crabs really were hunting birds. He had his proof a month later.

“In the middle of the night,” Laidre wrote, “I observed a coconut crab attack and kill an adult red-footed booby.”